Ex Parte Carlsson et al

Patent Trial and Appeal Board

Aug 15, 2013

11659059 (P.T.A.B. Aug. 15, 2013)

UNITED STATES PATENT AND TRADEMARKOFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
11/659,059 01/31/2007 Anders Carlsson TS1442 US 9841
23632 7590 08/15/2013
SHELL OIL COMPANY
P O BOX 2463
HOUSTON, TX 77252-2463
EXAMINER
SAHA, BIJAY S
ART UNIT PAPER NUMBER
1732
MAIL DATE DELIVERY MODE
08/15/2013 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte ANDERS CARLSSON and GIJSBERT JAN VAN HEERINGEN
____________

Appeal 2012-003030
Application 11/659,059
Technology Center 1700
____________

Before PETER F. KRATZ, ROMULO H. DELMENDO, and
DONNA M. PRAISS, Administrative Patent Judges.

PRAISS, Administrative Patent Judge

DECISION ON APPEAL

Appeal 2012-003030
Application 11/659,059

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The named inventors (hereinafter the “Appellants”)1 seek our review under
35 U.S.C. § 134(a) of a final rejection of claims 1, 5-21, and 28. We have
jurisdiction under 35 U.S.C. § 6(b). We affirm-in-part.

STATEMENT OF THE CASE
The invention relates to a process for the removal of mercaptans from a gas
stream. Specification (“Spec.”) 1. Mercaptan removal from a gas stream is
important for environmental and technical requirements. Id. Known processes for
the removal of mercaptans are generally based on physical absorption, solid bed
adsorption and/or chemical reaction and require large reactors to achieve the low
concentrations desired. Id. at 2-3. Representative claim 1 is reproduced below
(key limitations in dispute italicized):
1. A process for removing mercaptans from a feed gas stream
comprising natural gas or inert gas having a mercaptan concentration
of up to 40 vol %, the process comprising the steps of:
(a) passing said feed gas stream to a gas treating unit, wherein
said gas treating unit includes a mercaptan adsorbent bed, said
adsorbent bed consisting essentially of a mercaptan adsorbent
material selected from the group consisting of silica, silica gel,
alumina, silica-alumina, and molecular sieve, to thereby provide a
mercaptan adsorbent material loaded with mercaptan and to yield
therefrom a gas stream having a mercaptans concentration of less than
5 ppmv;
(b) ceasing said passing of said feed gas stream to said gas
treating unit, and, thereafter, contacting said mercaptan adsorbent
material loaded with mercaptan with an inert gas stream at an elevated
temperature or reduced pressure to transfer mercaptan from said
mercaptan adsorbent material loaded with mercaptan to said inert gas
stream to thereby yield from said gas treating unit a first gas stream

1 The Appellants identify the real party in interest as “Shell Oil Company.” Appeal
Brief filed August 17, 2011 (“App. Br.”) at 2.
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Application 11/659,059

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comprising mercaptans and at least 80% of gases selected from the
group of helium in the periodic table, nitrogen and hydrocarbonaceous
gases, wherein the concentration of CO2 in the first gas stream is
below 8 vol %;
(c) contacting said first gas stream with a
hydrodesulphurisation catalyst in the presence of hydrogen in a
hydrodesulphurisation unit to obtain a second gas stream comprising
inert gas, which is depleted of mercaptans and enriched in H2S; and
(d) removing H2S from the second gas stream in a H2S removal
unit to obtain a purified gas stream comprising inert gas, which is
depleted of H2S and mercaptans to a level of below 1 ppmv.
App. Br. 16 (Claims App’x).
Claim 9 depends from claim 1 and recites “wherein the H2S removal unit
comprises an H2S adsorbent bed.” Id. at 17. Claim 10 depends from claim 9 and
recites “wherein the H2S adsorbent bed comprises [sic] further comprises titania.”
Id.
The Examiner rejected claims 1, 5-21, and 28, which are all of the pending
claims, under 35 U.S.C. § 103(a) as follows:
1. Claims 1, 5-7, 9, and 13-19 over Frye2 in view of Lagas3;
2. Claims 8 and 20 over Frye in view of Lagas and further in view of Dew4;
3. Claims 10 over Frye in view of Lagas and further in view of Johnson5;
4. Claim 11 over Frye in view of Lagas and further in view of Blytas6;
5. Claims 12 and 21 over Frye in view of Lagas and further in view of Da
Silva7;

2 US 6,531,052, issued March 11, 2003.
3 WO 97/26069, published July 24, 1997.
4 US 4,176,087, issued November 27, 1979.
5 US 6,702,937, issued March 9, 2004.
6 US 4,356,155, issued October 26, 1982.
7 US 6,638,419, issued October 28, 2003.
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Application 11/659,059

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6. Claim 28 over Frye in view of Lagas and further in view of Loy8.
Examiner’s Answer mailed October 24, 2011 (“Ans.”) 4-14.

DISCUSSION
The Appellants limit their arguments for the patentability of claims 1, 5-7, 8,
9, 11-21, and 28 to the subject matter common to independent claims 1 and 14.
App. Br. 5-11, 13-14. Therefore, we confine our discussion to claims 1 and 10.
Claims 5-7, 8, 9, 11-21, and 28 stand or fall with claim 1. See 37 C.F.R.
§ 41.37(c)(1)(vii); see also Hyatt v. Dudas, 551 F.3d 1307, 1313 (Fed. Cir. 2008).
The Examiner found that Frye discloses removal of sulfur including
mercaptans from a hydrocarbon fluid stream to a concentration less than 5 ppmv in
accordance with claim 1, step (a) (Ans. 5 (citing Frye, claim 1, col. 1, l. 66, Fig.
1)). The Examiner further found that Frye discloses the regeneration of adsorbent
column where the bed is contacted with an atmosphere containing more than 99%
nitrogen and less than 1 vol% oxygen and a temperature of about 500°C in
accordance with claim 1, step (b) (id. at 5-6 (citing Frye, col. 2, ll. 44, 51, col. 3,
ll. 28, 41)). The Examiner acknowledged that Frye “does not explicitly disclose
the hydrodesulphurization of the sulfur species containing gas stream” (id. at 6)
required by claim 1, step (c), but found that “[o]ne of ordinary skill in the art, at the
time of the invention would have been motivated [after using the mercaptans
absorbing bed of Frye] to use the additional process of H2S separation [of Lagas]
because the hydrodesulfurization process converts the mercaptans containing gas
stream into two streams with and without H2S.” Id. at 7. The Examiner further
found it would have been obvious to remove and use the sulfur in the H2S
containing gas stream as required by claim 1, step (d). Id.

8 US 5,321,102, issued June 14, 1994.
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Application 11/659,059

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The Examiner also finds that Johnson “teaches preferred support on the basis
of the catalyst chemistry (col 5 lines 55-58) suitable at high temperature and
pressures (col 5 line 10 Johnson).” Id. at 11. The Examiner determined that it
would have been obvious to a person of ordinary skill in the art to utilize “the
titania for the support” taught by Johnson in the combination of Frye and Lagas
above. Id.
The Appellants contend that the Examiner’s rejection is flawed because Frye
“teaches away from using a non-silver containing adsorbent” (App. Br. 8,
emphasis omitted) and Frye “refers to liquid hydrocarbon fluids . . . [not] gases”
(id. at 10). The Appellants further contend that Lagas “employs a chemical and/or
physical solvent (i.e., a liquid absorbent) in the first step to remove mercaptans
. . . .” Id. (emphasis omitted). The Appellants also contend that Johnson discloses
alumina and titania “only as possible support materials in Fischer-Tropsch
catalysts” and “does not teach alumina or titania as part of an H2S adsorbent bed.”
Id. at 12.
Thus, the dispositive issues arising from these contentions are:
1. Did the Appellants show reversible error in the Examiner’s conclusion
that a person of ordinary skill in the art would have found it obvious to
use a hydrodesulphurization process for H2S separation after using a
mercaptans absorbing bed in order to convert the mercaptans containing
gas stream into two streams with and without H2S, as recited in claim 1,
in view of the applied prior art?
2. Did the Appellants show reversible error in the Examiner’s conclusion
that a person of ordinary skill in the art would have found it obvious to
use titania in the mercaptans absorbing bed as recited in claim 10, in view
of the applied prior art?
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Application 11/659,059

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Claim 1
As the Examiner points out, Frye teaches a process for the removal of
mercaptans from hydrocarbon fluids using a regenerable adsorbent with the
temperature and concentrations recited in steps (a) and (b) of claim 1. Ans. 5-6.
Appellants dispute the nature of the “fluid” feed stream in Frye extends to natural
gas and that the nature of the adsorbent includes silica or alumina alone. App. Br.
7-10. The Examiner finds that the term “fluid” applies to both liquids and gases.
Ans. 5.
Appellants concede that “the term ‘fluid’ can as a general matter refer to
either a liquid or a gas” but argue “as used in Frye [it] refers to liquid hydrocarbon
fluids.” App. Br. 10. Even if Appellants are correct that Frye only refers to a
hydrocarbon feed stream of a liquid nature by the manner in which Frye employs
the term “fluid” or “hydrocarbon fluids”, the Examiner further determines, in
essence, that Frye’s mercaptan adsorbing material alumina would be expected to
be capable of adsorbing mercaptan from a fluid whether liquid or gas. Ans. 20-21,
and 24. Appellants have not directed us to any evidence or reasoning establishing
that the sulfur species present in a liquid hydrocarbon fluid are so different from
those present in natural gas that the process of Frye would not have been expected
to be applicable to removing mercaptans from a gas stream using Frye’s aluminum
adsorbent substrate with or without a silver compound. See App. Br. 9-10; Reply
Br. 4. In this regard, we agree with the Examiner that the transitional phrase
“consisting essentially of” does not exclude silver oxide from the adsorbent
required by the appealed claims. Ans. 21. In the absence of any reason for natural
gas to behave any differently from a liquid hydrocarbon, we find no error in the
Examiner’s conclusion that a person of ordinary skill in the art would have found it
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Application 11/659,059

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obvious to apply the process of Frye to a natural gas feed stream for the purpose of
removing mercaptans.
We further find that the Examiner’s determination that Frye discloses
alumina or alumina combined with silica as the solid adsorbent substrate is
supported by the record. The Examiner correctly finds that Frye broadly teaches
“alumina” and “silica” and that the “addition of other oxides such as silver oxide
makes the mercaptan adsorption even better” (Ans. 5, 19; citing Frye, col. 2, l. 10,
Fig. 1). A reference cannot be said to “teach away” from the method of claim 1 by
merely offering a preferred alternative. See, e.g., In re Fulton, 391 F.3d 1195,
1201 (Fed. Cir. 2004) (explaining “[t]he prior art’s mere disclosure of more than
one alternative does not constitute a teaching away from any of these alternatives
because such disclosure does not criticize, discredit, or otherwise discourage the
solution claimed”).
Appellants’ argument that the first absorption step in Lagas is a chemical,
physical or chemical/physical absorption agent rather than a bed of a solid
mercaptan-adsorbent material and therefore does not overcome the deficiencies in
Frye (App. Br. 10-11) is not persuasive. The purpose for which Lagas is relied
upon by the Examiner is for including a subsequent hydrodesulphurization catalyst.
Ans. 6-7. Thus, the Examiner relies on Frye for teaching steps (a) and (b) and on
Lagas for teaching steps (c) and (d) in rejecting claim 1 over the combination of
Frye and Lagas. Id. at 5-7. One cannot show nonobviousness by attacking
references individually where the rejections are based on combinations of
references. See In re Keller, 642 F.2d 413, 426 (CCPA 1981); In re Merck & Co.,
Inc., 800 F.2d 1091, 1097 (Fed. Cir. 1986).
For the reasons provided in the Answer, including the Response to
Argument section, and above, we uphold the Examiner’s rejection of claim 1.
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Application 11/659,059

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Claim 10
The Examiner relies upon Johnson for teaching the use of titania as recited
in claim 10. Ans. 11. Claim 10 depends from claim 9, which depends from
claim 1 such that “the H2S removal unit” recited in claim 1 further “comprises an
H2S adsorbent bed” in claim 9 and “the H2S adsorbent bed comprises further
comprises titania” in claim 10. The Examiner does not dispute Appellants’
argument that Johnson discloses titania and alumina only as possible support
materials in Fischer-Tropsch catalysts and not as part of an H2S adsorbent bed.
Ans. 26-27. The Examiner does not direct us to any evidence that the Fischer-
Tropsch catalysts supported by titania are capable of functioning as an H2S
adsorbent bed as claimed in claim 10. Therefore, we agree with Appellants that
the Examiner harmfully erred in rejecting claim 10 over the combination of Frye,
Lagas, and Johnson.

SUMMARY

The Examiner’s rejection under 35 U.S.C. § 103(a) of claims 1, 5-7, 8, 9, 11-
21, and 28 is affirmed.
The Examiner’s rejection under 35 U.S.C. § 103(a) of claim 10 is reversed.
No time period for taking any subsequent action in connection with this
appeal may be extended under 37 C.F.R. § 1.136(a).

AFFIRMED-IN-PART
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